> Biological and cultural evolution do reveal a clear directional> development. Biologically, early forms were all relatively simple, but> more complex forms evolved from, and then alongside, simpler ones.

No evolution is not directional. The early forms may have been simple,
but many of them are still around, whereas many complex organisms (the
dinosaurs, for instance) have become extinct. So which is the more
evolutionarily viable? There is also no way to compare species that exist
at this (or any one) moment in history to each other. Each has evolved
according to different environmental and biological circumstances. Who is
to dsay that a dolphin's fin is better than a shark's simply because one
has a more complex brain? Homo sapiens did not evolve from the chimp,
they both evolved from a common ancestor, but, in the mean time, both
species have continued to evolve in their own way.